usr.sbin/lpr/common_source/rmjob.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)rmjob.c  8.2 (Berkeley) 4/28/95
  34  * $FreeBSD: src/usr.sbin/lpr/common_source/rmjob.c,v 1.12.2.5 2001/06/25 01:00:56 gad Exp $
  35  * $DragonFly: src/usr.sbin/lpr/common_source/rmjob.c,v 1.4 2004/12/18 22:48:03 swildner Exp $
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/uio.h>
  40
  41 #include <ctype.h>
  42 #include <dirent.h>
  43 #include <errno.h>
  44 #include <signal.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #define psignal foil_gcc_psignal
  49 #define sys_siglist foil_gcc_siglist
  50 #include <unistd.h>
  51 #undef psignal
  52 #undef sys_siglist
  53
  54 #include "lp.h"
  55 #include "lp.local.h"
  56 #include "pathnames.h"
  57
  58 /*
  59  * rmjob - remove the specified jobs from the queue.
  60  */
  61
  62 /*
  63  * Stuff for handling lprm specifications
  64  */
  65 static char     root[] = "root";
  66 static int      all = 0;                /* eliminate all files (root only) */
  67 static int      cur_daemon;             /* daemon's pid */
  68 static char     current[7+MAXHOSTNAMELEN];  /* active control file name */
  69
  70 extern uid_t    uid, euid;              /* real and effective user id's */
  71
  72 static  void    alarmhandler(int _signo);
  73 static  void    do_unlink(char *_file);
  74
  75 void
  76 rmjob(const char *printer)
  77 {
  78         int i, nitems;
  79         int assasinated = 0;
  80         struct dirent **files;
  81         char *cp;
  82         struct printer myprinter, *pp = &myprinter;
  83
  84         init_printer(pp);
  85         if ((i = getprintcap(printer, pp)) < 0)
  86                 fatal(pp, "getprintcap: %s", pcaperr(i));
  87         if ((cp = checkremote(pp))) {
  88                 printf("Warning: %s\n", cp);
  89                 free(cp);
  90         }
  91
  92         /*
  93          * If the format was `lprm -' and the user isn't the super-user,
  94          *  then fake things to look like he said `lprm user'.
  95          */
  96         if (users < 0) {
  97                 if (getuid() == 0)
  98                         all = 1;        /* all files in local queue */
  99                 else {
 100                         user[0] = person;
 101                         users = 1;
 102                 }
 103         }
 104         if (!strcmp(person, "-all")) {
 105                 if (from_host == local_host)
 106                         fatal(pp, "The login name \"-all\" is reserved");
 107                 all = 1;        /* all those from 'from_host' */
 108                 person = root;
 109         }
 110
 111         seteuid(euid);
 112         if (chdir(pp->spool_dir) < 0)
 113                 fatal(pp, "cannot chdir to spool directory");
 114         if ((nitems = scandir(".", &files, iscf, NULL)) < 0)
 115                 fatal(pp, "cannot access spool directory");
 116         seteuid(uid);
 117
 118         if (nitems) {
 119                 /*
 120                  * Check for an active printer daemon (in which case we
 121                  *  kill it if it is reading our file) then remove stuff
 122                  *  (after which we have to restart the daemon).
 123                  */
 124                 if (lockchk(pp, pp->lock_file) && chk(current)) {
 125                         seteuid(euid);
 126                         assasinated = kill(cur_daemon, SIGINT) == 0;
 127                         seteuid(uid);
 128                         if (!assasinated)
 129                                 fatal(pp, "cannot kill printer daemon");
 130                 }
 131                 /*
 132                  * process the files
 133                  */
 134                 for (i = 0; i < nitems; i++)
 135                         process(pp, files[i]->d_name);
 136         }
 137         rmremote(pp);
 138         /*
 139          * Restart the printer daemon if it was killed
 140          */
 141         if (assasinated && !startdaemon(pp))
 142                 fatal(pp, "cannot restart printer daemon\n");
 143         exit(0);
 144 }
 145
 146 /*
 147  * Process a lock file: collect the pid of the active
 148  *  daemon and the file name of the active spool entry.
 149  * Return boolean indicating existence of a lock file.
 150  */
 151 int
 152 lockchk(struct printer *pp, char *slockf)
 153 {
 154         FILE *fp;
 155         int i, n;
 156
 157         seteuid(euid);
 158         if ((fp = fopen(slockf, "r")) == NULL) {
 159                 if (errno == EACCES)
 160                         fatal(pp, "%s: %s", slockf, strerror(errno));
 161                 else
 162                         return(0);
 163         }
 164         seteuid(uid);
 165         if (!getline(fp)) {
 166                 fclose(fp);
 167                 return(0);              /* no daemon present */
 168         }
 169         cur_daemon = atoi(line);
 170         if (kill(cur_daemon, 0) < 0 && errno != EPERM) {
 171                 fclose(fp);
 172                 return(0);              /* no daemon present */
 173         }
 174         for (i = 1; (n = fread(current, sizeof(char), sizeof(current), fp)) <= 0; i++) {
 175                 if (i > 5) {
 176                         n = 1;
 177                         break;
 178                 }
 179                 sleep(i);
 180         }
 181         current[n-1] = '\0';
 182         fclose(fp);
 183         return(1);
 184 }
 185
 186 /*
 187  * Process a control file.
 188  */
 189 void
 190 process(const struct printer *pp, char *file)
 191 {
 192         FILE *cfp;
 193
 194         if (!chk(file))
 195                 return;
 196         seteuid(euid);
 197         if ((cfp = fopen(file, "r")) == NULL)
 198                 fatal(pp, "cannot open %s", file);
 199         seteuid(uid);
 200         while (getline(cfp)) {
 201                 switch (line[0]) {
 202                 case 'U':  /* unlink associated files */
 203                         if (strchr(line+1, '/') || strncmp(line+1, "df", 2))
 204                                 break;
 205                         do_unlink(line+1);
 206                 }
 207         }
 208         fclose(cfp);
 209         do_unlink(file);
 210 }
 211
 212 static void
 213 do_unlink(char *file)
 214 {
 215         int     ret;
 216
 217         if (from_host != local_host)
 218                 printf("%s: ", local_host);
 219         seteuid(euid);
 220         ret = unlink(file);
 221         seteuid(uid);
 222         printf(ret ? "cannot dequeue %s\n" : "%s dequeued\n", file);
 223 }
 224
 225 /*
 226  * Do the dirty work in checking
 227  */
 228 int
 229 chk(char *file)
 230 {
 231         int *r, n;
 232         char **u, *cp;
 233         FILE *cfp;
 234
 235         /*
 236          * Check for valid cf file name (mostly checking current).
 237          */
 238         if (strlen(file) < 7 || file[0] != 'c' || file[1] != 'f')
 239                 return(0);
 240
 241         if (all && (from_host == local_host || !strcmp(from_host, file+6)))
 242                 return(1);
 243
 244         /*
 245          * get the owner's name from the control file.
 246          */
 247         seteuid(euid);
 248         if ((cfp = fopen(file, "r")) == NULL)
 249                 return(0);
 250         seteuid(uid);
 251         while (getline(cfp)) {
 252                 if (line[0] == 'P')
 253                         break;
 254         }
 255         fclose(cfp);
 256         if (line[0] != 'P')
 257                 return(0);
 258
 259         if (users == 0 && requests == 0)
 260                 return(!strcmp(file, current) && isowner(line+1, file));
 261         /*
 262          * Check the request list
 263          */
 264         for (n = 0, cp = file+3; isdigit(*cp); )
 265                 n = n * 10 + (*cp++ - '0');
 266         for (r = requ; r < &requ[requests]; r++)
 267                 if (*r == n && isowner(line+1, file))
 268                         return(1);
 269         /*
 270          * Check to see if it's in the user list
 271          */
 272         for (u = user; u < &user[users]; u++)
 273                 if (!strcmp(*u, line+1) && isowner(line+1, file))
 274                         return(1);
 275         return(0);
 276 }
 277
 278 /*
 279  * If root is removing a file on the local machine, allow it.
 280  * If root is removing a file from a remote machine, only allow
 281  * files sent from the remote machine to be removed.
 282  * Normal users can only remove the file from where it was sent.
 283  */
 284 int
 285 isowner(char *owner, char *file)
 286 {
 287         if (!strcmp(person, root) && (from_host == local_host ||
 288             !strcmp(from_host, file+6)))
 289                 return (1);
 290         if (!strcmp(person, owner) && !strcmp(from_host, file+6))
 291                 return (1);
 292         if (from_host != local_host)
 293                 printf("%s: ", local_host);
 294         printf("%s: Permission denied\n", file);
 295         return(0);
 296 }
 297
 298 /*
 299  * Check to see if we are sending files to a remote machine. If we are,
 300  * then try removing files on the remote machine.
 301  */
 302 void
 303 rmremote(const struct printer *pp)
 304 {
 305         int i, elem, firstreq, niov, rem, totlen;
 306         char buf[BUFSIZ];
 307         void (*savealrm)(int);
 308         struct iovec *iov;
 309
 310         if (!pp->remote)
 311                 return; /* not sending to a remote machine */
 312
 313         /*
 314          * Flush stdout so the user can see what has been deleted
 315          * while we wait (possibly) for the connection.
 316          */
 317         fflush(stdout);
 318
 319         /*
 320          * Counting:
 321          *      4 == "\5" + remote_queue + " " + person
 322          *      2 * users == " " + user[i] for each user
 323          *      requests == asprintf results for each request
 324          *      1 == "\n"
 325          * Although laborious, doing it this way makes it possible for
 326          * us to process requests of indeterminate length without
 327          * applying an arbitrary limit.  Arbitrary Limits Are Bad (tm).
 328          */
 329         if (users > 0)
 330                 niov = 4 + 2 * users + requests + 1;
 331         else
 332                 niov = 4 + requests + 1;
 333         iov = malloc(niov * sizeof *iov);
 334         if (iov == 0)
 335                 fatal(pp, "out of memory in rmremote()");
 336         iov[0].iov_base = "\5";
 337         iov[1].iov_base = pp->remote_queue;
 338         iov[2].iov_base = " ";
 339         iov[3].iov_base = all ? "-all" : person;
 340         elem = 4;
 341         for (i = 0; i < users; i++) {
 342                 iov[elem].iov_base = " ";
 343                 iov[elem + 1].iov_base = user[i];
 344                 elem += 2;
 345         }
 346         firstreq = elem;
 347         for (i = 0; i < requests; i++) {
 348                 asprintf((char **)&iov[elem].iov_base, " %d", requ[i]);
 349                 if (iov[elem].iov_base == 0)
 350                         fatal(pp, "out of memory in rmremote()");
 351                 elem++;
 352         }
 353         iov[elem++].iov_base = "\n";
 354         for (totlen = i = 0; i < niov; i++)
 355                 totlen += (iov[i].iov_len = strlen(iov[i].iov_base));
 356
 357         savealrm = signal(SIGALRM, alarmhandler);
 358         alarm(pp->conn_timeout);
 359         rem = getport(pp, pp->remote_host, 0);
 360         signal(SIGALRM, savealrm);
 361         if (rem < 0) {
 362                 if (from_host != local_host)
 363                         printf("%s: ", local_host);
 364                 printf("connection to %s is down\n", pp->remote_host);
 365         } else {
 366                 if (writev(rem, iov, niov) != totlen)
 367                         fatal(pp, "Lost connection");
 368                 while ((i = read(rem, buf, sizeof(buf))) > 0)
 369                         fwrite(buf, 1, i, stdout);
 370                 close(rem);
 371         }
 372         for (i = 0; i < requests; i++)
 373                 free(iov[firstreq + i].iov_base);
 374         free(iov);
 375 }
 376
 377 /*
 378  * Return 1 if the filename begins with 'cf'
 379  */
 380 int
 381 iscf(struct dirent *d)
 382 {
 383         return(d->d_name[0] == 'c' && d->d_name[1] == 'f');
 384 }
 385
 386 void
 387 alarmhandler(int signo __unused)
 388 {
 389         /* the signal is ignored */
 390         /* (the '__unused' is just to avoid a compile-time warning) */
 391 }